Background/Objectives: Chronic primary pain (CPP) is a new diagnostic category including chronic pain conditions lacking clinical signs or a clear etiopathogenetic origin. These disorders may share a common neural mechanism known as central sensitization, where nociceptive neurons become hyper-responsive to standard or subthreshold pain stimuli, resulting in pain hyper-sensitivity. In this context, non-invasive brain stimulation (NIBS) appears to be a promising tool for improving CPP symptoms by targeting maladaptive brain activity and connectivity. To date, the effects of NIBS on CPP symptoms remain unexplored. To fill this gap, we conducted a meta-analysis, investigating the effect of NIBS in improving the three core symptoms of CPP, namely pain intensity, emotional distress, and functional disability. Methods: Following PRISMA guidelines, we screened four databases up to February 2025 for English-language, peer-reviewed randomized clinical trials that included CPP patients treated with NIBS and reported pre/post or follow-up scores on validated measures of at least one core symptom. Quality of life was examined as an additional outcome. Results: Fifty-four studies were included, with 1371 participants receiving real stimulation and 1103 sham. Findings highlighted that real stimulation improved CPP symptoms immediately after treatment and at one-month follow-up. Meta-regressions showed that longer CPP duration reduced short-term effects on emotional distress and diminished all outcomes at one-month follow-up. Conclusions: Further research is needed to establish standardized NIBS protocols for CPP management, to investigate the effectiveness at longer follow-up periods, and to test whether combining NIBS with other interventions enhances treatment effectiveness and durability.

Background: Interoception has been proposed as a key mechanism underlying impulsive behaviours, including maladaptive eating. However, the brain mechanisms supporting the interaction between interoception and impulsivity across different reward types remain unclear. This study investigated whether modulating the right insula and the dorsal anterior cingulate cortex (dACC) using high-definition transcranial direct current stimulation (HD-tDCS) could affect interoceptive accuracy and impulsive decision-making. Methods: Model-based HD-tDCS montages were defined to target the right insula and dACC. Two behavioural paradigms were administered: (i) the heartbeat detection task (HBD) to assess interoceptive accuracy and (ii) two versions of the delay discounting (DD) task with food and monetary rewards to measure impulsivity. Heart rate variability (HRV) was recorded as an index of autonomic activity. HD-tDCS was delivered online during the HBD, while DD tasks were completed offline. Twenty-four participants took part in four sessions in a within-subject design: baseline DD tasks, anodal HD-tDCS targeting the insula, dACC, or sham stimulation. Results: Stimulation of both the insula and dACC reduced participants’ ability to detect synchronous heartbeat while improving accuracy in exteroceptive trials. Discounting rates significantly increased following insula stimulation. Moreover, HD-tDCS effects on DD performance varied depending on reward type. Conclusions: These findings suggest differential contributions of the dACC and insula in interoceptive and exteroceptive processing and support the effect of HD-tDCS combined with interoceptive tasks to modulate impulsive decision-making. Reward-specific effects highlight the importance of stimulus type when designing interventions for impulsive eating behaviours.

Background/Objectives: Food waste contributes to environmental, social, economic, and nutritional losses. In this context, school canteens represent a key setting for shaping sustainable and healthy early dietary behaviors. This pilot study aimed to evaluate the implementation of a combined digital meal-planning and educational intervention and to explore changes in plate waste, food-related responses, and perceived inclusivity and involvement. Methods: An uncontrolled pre-post pilot study in one preschool and one primary school in a single municipality was conducted. The intervention combined a digital lunch-planning tool, enabling menu and portion selection, with educational workshops on food and sustainability. Plate waste was weighed during two menu-matched weeks, one before and one after implementation. Parent and child questionnaires assessing dietary habits, emotional responses to food and food waste images, perceived inclusivity and involvement, and well-being were recorded. Results: Of 159 enrolled pupils, 155 registered on the platform and 152 used it at least once. Overall, 82.3% of meals were pre-planned through the platform. Questionnaires were completed at baseline by 93 participants and at follow-up by 60, with 48 participating at both time points. Exploratory analyses identified differences over time in some emotional-response ratings and higher parent-rated inclusivity and involvement at follow-up. Across the two observation weeks, measured plate waste decreased from 0.066 to 0.038 kg per meal attendance, an observed reduction of 42.1%. As portion sizes could be reduced or omitted, lower discarded quantities could be related to both increased food consumption and/or reduction in the amount of food prepared. Conclusions: High platform uptake supports the operational feasibility of implementing this combined programme in the participating schools. The observed differences are exploratory: the uncontrolled design, brief waste-measurement periods, and questionnaire attrition preclude causal attribution. Controlled studies with repeated measurements and longer follow-up are needed to evaluate effectiveness and transferability.